Ultra high performance concrete bridge decks reinforced with high-strength steel or fiber reinforced polymers

Among the states, Florida has the largest stock of moveable bridges, most of which with open grid steel decks. These decks are often associated with poor rideability, high noise levels, susceptibility to fatigue damage, and high maintenance costs. To address these issues, two alternative lightweight shallow deck systems are proposed. One with a thin flange, narrow ribs across the deck span, and short transverse ribs, made with ultra high performance concrete (UHPC) and high-strength MMFX steel (HSS). Another one is a hollow core deck made with UHPC and fiber reinforced polymer (FRP) tubes. A large number of experiments, both static and fatigue, were conducted on simple and continuous two-span models of the UHPC-HSS deck system with single and multiple ribs in the cross section. Limited tests were carried out on the UHPC-FRP deck system. The UHPC-HSS deck system was shown to satisfy the strength serviceability requirements, whereas the UHPC-FRP deck system required additional stiffness. In addition, a series of pullout and beam tests were conducted to determine the bond and development for high-strength MMFX steel in UHPC. A detailed comparison between experimental results and the code recommendations showed that ACI 408R-03 compares more favorably than the ACI 318-08 for the development lengths of MMFX in UHPC.